1. Field of the Invention
The present invention relates to an optical disk drive, and more particularly to an external optical disk drive with a locking mechanism for releasing or locking its cover.
2. Description of the Related Art
An optical disk drive has an independent housing (referred to as an external optical disk drive), and is connected to a host computer via a signal cable to transmit data to the computer system. In addition, the external optical disk drive may transmit data to the users via an audio cable.
In prior art, the conventional disk loading and disk ejection methods include disk-tray type and cover-lifting type. Regarding the disk-tray type disk drive, the optical disk can be placed on the disk tray when a disk tray motor pulls the disk tray to what so called pull-out position. As shown in FIG. 1, the disk-tray optical disk drive includes a rectangular-shaped slit 11 surrounding the disk tray. However, due to the slit 11, the disk tray may be jammed by foreign objects during loading and ejection of the optical disk. Besides, the cover-lifting optical disk drive is normally applied to multimedia playback device. FIG. 2 and FIG. 3 show a conventional locking mechanism for a cover-lifting optical disk drive. The cover-lifting optical disk drive includes a cover 100 and a lower housing assembly 200. The cover 100 includes an opening 101 at its front edge, a rod 102 extending downwardly the front edge and beside the opening 101, and a rotary shaft 103 at its rear edge. The rotary shaft 103 is pivotally coupled to the lower housing assembly 200 so that the cover 100 can be pivoted with respect to the lower cover assembly 200. To effectively utilize the space occupied by the optical disk drive, the rotary shaft 103 is not located at a central portion of the rear edge of the cover 100. Further, the hook 300 engages with the opening 101 for the purpose of securing the cover 100 to the lower housing assembly 200. When the cover 100 is locked, a force F is applied to the rod 102 of the cover 100 by a torsion spring 400. As described above, the force F of the torsion spring 400 is applied to the rod 102 that is not located at the central portion of the front edge of the cover 100. Thus, the rotary shaft 103 that is slightly open. Due to a displacement D at the front edge of the cover 100, the cover 100 is deformed. The deformation of cover 100 may be aggravated during transport when environmental temperature is high, thereby rendering the finished product unusable prior to selling.
Accordingly, there is a need to develop a locking mechanism for use in an external optical disk drive.
It is an object of the present invention to provide a locking mechanism for an external optical disk drive that can effectively eliminate the deformation of a cover.
It is another object of the present invention to provide an external optical disk drive that a locking mechanism is used to secure a cover smoothly.
Accordingly, the present invention provides a locking mechanism for an external optical disk drive without additional torsion spring. In one embodiment of the present invention, the locking mechanism is disposed under the cover and includes a curved extension portion, a motor and a gear set. The gear set is driven by the motor to drive the curved extension portion of the cover, thereby opening the cover.
Thus, the object of the present invention is to provide an external optical disk drive without deformation, such that both quality and appearance of the cover are improved.